JP2006312905A - Cylinder block and its assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder block constructed to be separated into a cylinder liner portion and a cylinder block body for more easily securing the supporting rigidity of the cylinder liner portion. <P>SOLUTION: The cylinder block 3 is constructed to be separated into the cylinder liner portion 21 as part of the wall face of a cylinder and the cylinder block body 30 having a cylinder outer wall 32 encircling the cylinder liner portion 21. An approximately flat upper deck portion 22 provided on the top of the cylinder liner portion 21 is supported on a top 32a of the cylinder outer wall 32. A shim 70 is held between a bottom face 28 of the cylinder liner portion 21 and the cylinder block body 30 (a bottom face 41) opposed to the bottom face 28. Thus, the cylinder liner portion 21 is further supported at its lower part on the cylinder block body 30 via the shim 70. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an engine cylinder block mounted on a vehicle or the like and an assembling method thereof.

In an engine mounted on a vehicle or the like, a cylinder head, a gasket, and a cylinder block are fixed by a fastening member such as a bolt (for example, Patent Document 1).
On the other hand, there is a cylinder block that is divided into a cylinder liner portion that constitutes the wall surface of the cylinder and a cylinder block body that has a cylinder outer wall portion that constitutes an outer wall surrounding the cylinder liner portion. An example of such a cylinder block is shown in FIG. In FIG. 8, the cross-sectional structure between the cylinder bores is shown on the right side of the alternate long and short dash line E, and the cross-sectional structure along the center axis of the cylinder bore is shown on the left side of the same dashed line E.

As shown in FIG. 8, this cylinder block is divided into a cylinder liner part 121 that constitutes the wall surface of the cylinder and a cylinder block main body 130 that has a cylinder outer wall part 132 that constitutes the outer wall surrounding the cylinder liner part 121. ing. The cylinder liner 121 has a substantially flat upper deck 122 supported by the top surface 132 a of the cylinder outer wall 132. The cylinder liner 121 is loosely inserted into the hole 140 of the cylinder block main body 130. Yes. The outer peripheral surface of the cylinder liner 121 and the inner peripheral surface of the hole 140 are sealed by the seal member 61. An upper deck portion 122 is placed on the top surface 132 a of the cylinder outer wall portion 132, and a cylinder head 120 is placed on the upper surface of the upper deck portion 122 via a gasket 104. The cylinder head 120, the gasket 104, the upper deck portion 122, and the cylinder outer wall portion 132 are fastened and fixed by the head bolt 170.
Japanese Patent Laid-Open No. 11-200941 JP 2002-97997 A

  By the way, in the cylinder block as shown in FIG. 8, when the head bolt 170 is tightened, the fastening force acts on the upper surface of the cylinder liner portion 121 via the gasket 104, so that the cylinder liner portion 121 faces downward. Pressed.

  Here, as shown in FIG. 8, in the fixing mode in which the upper deck portion 122 is supported by the top surface 132a of the cylinder outer wall portion 132 and the cylinder liner portion 121 is fixed to the cylinder block body 130 by this, the cylinder liner portion is fixed. Since 121 is in a so-called cantilever state, it is difficult to ensure sufficient support rigidity of the cylinder liner portion 121. Therefore, the cylinder liner portion 121 is easily deformed downward by the fastening force of the head bolt 170. When the cylinder liner 121 is deformed downward in this way, the surface pressure of the gasket 104 is likely to decrease (particularly the surface pressure between the cylinder bores). Further, deformation of the cylinder bore or the like is likely to occur due to the downward deformation of the cylinder liner portion 121.

  Therefore, in order to suppress such deformation of the cylinder liner portion 121, it is desirable that the bottom surface 128 of the cylinder liner portion 121 is also supported by the cylinder block main body 130. For example, as shown in the cross-sectional structure on the left side of the alternate long and short dash line E in FIG. 8, a support portion 141 (illustrated by a two-dot chain line) that supports the bottom surface 128 of the cylinder liner portion 121 is provided below the hole 140. If the bottom surface 128 is supported by the upper surface 141a of the support portion 141, the downward deformation of the cylinder liner portion 121 can be suppressed.

  However, when the cylinder liner portion 121 is supported not only by the upper deck portion 122 but also by the bottom surface 128, the dimension X from the top surface 132 a of the cylinder outer wall portion 132 to the upper surface 141 a or the lower surface of the upper deck portion 122 from the bottom surface of the cylinder liner portion 121. When the dimension Y up to the bottom surface 128 varies, the dimension difference between the dimension X and the dimension Y also varies. As described above, when the dimensional difference between the dimensions X and Y varies, the degree of pinching of the cylinder liner 121 varies, and the support rigidity of the cylinder liner 121 varies. Therefore, it is necessary to process each dimension X and Y with high accuracy. That is, it is necessary to reduce (toughen) the required tolerance for each of the dimensions X and Y to suppress the variation in the dimension difference. However, if the required tolerances of the cylinder liner 121 and the cylinder block main body 130 are reduced in this way, inconveniences such as an increase in manufacturing cost and deterioration in workability are likely to occur.

  In the cylinder block described in Patent Document 2, a flange is provided below the cylinder liner, and the lower surface of the flange is supported by the cylinder block body. In such a structure, high accuracy is required when processing the shape of the flange and the cylinder block body. For example, high machining accuracy with respect to the perpendicularity of the cylinder liner to the bottom surface of the flange, the parallelism between the bottom surface of the flange and the top surface of the cylinder liner, or the parallelism between the surface of the cylinder block body that the bottom surface of the flange contacts and the top surface of the cylinder block body Is required. If the machining accuracy is not sufficiently ensured, the cylinder liner may be deformed when the cylinder head is assembled.

  Incidentally, even in the cylinder block described in Patent Document 2, strict values are required for each tolerance with respect to the dimension from the upper surface of the cylinder liner to the front surface of the flange and the dimension from the upper surface of the cylinder block body to the surface with which the flange abuts. The

  The present invention has been made in view of such circumstances, and an object thereof is to more easily ensure the support rigidity of the cylinder liner portion in the cylinder block configured to be divided into the cylinder liner portion and the cylinder block body. It is to provide a cylinder block.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is divided into a cylinder liner part constituting a wall surface of the cylinder and a cylinder block body having a cylinder outer wall part constituting an outer wall surrounding the cylinder liner part, and the cylinder liner part In the cylinder block in which a substantially flat upper deck portion provided at the top of the cylinder block is supported on the top surface of the cylinder outer wall portion, a member for supporting a lower portion of the cylinder liner portion to the cylinder block body, The gist of the invention is to provide an interposed member sandwiched between the cylinder liner portion and the cylinder block body.

  According to this configuration, in the cylinder block divided into the cylinder liner portion and the cylinder block main body, the cylinder liner portion is fixed to the top surface of the cylinder outer wall portion, that is, the cylinder block main body via the upper deck portion. In addition to such a fixing mode, according to the configuration, the cylinder liner body is also supported below the cylinder liner portion by the interposition member. For this reason, the support rigidity of the cylinder liner portion can be reliably ensured, so that a reduction in the surface pressure of the gasket, deformation of the cylinder bore, and the like can be suitably suppressed.

  Here, in the same configuration, when the lower portion of the cylinder liner portion is supported by the cylinder block body, the interposed member is sandwiched between the lower portion of the cylinder liner portion and the cylinder block body. Therefore, even if the dimensional difference between the dimension X and the dimension Y as described above varies, the variation is absorbed by the deformation of the intervention member. Therefore, even if the tolerances of the dimensions X and Y are not reduced so much, variations in the support rigidity of the cylinder liner portion can be suppressed. Thus, according to this configuration, it is possible to ensure the support rigidity and suppress variations in the support rigidity without requiring so high accuracy when processing the cylinder liner portion and the cylinder block body. That is, the support rigidity of the cylinder liner portion can be more easily ensured as compared with the case where the lower portion of the cylinder liner portion is directly brought into contact with the cylinder block body to ensure the support rigidity of the cylinder liner portion. Become.

In addition, as said intervention member, what is called a shim etc. used in order to carry out fine adjustment of a clearance gap etc. are mentioned.
According to a second aspect of the present invention, in the cylinder block according to the first aspect, the interposed member is sandwiched between a bottom surface of the cylinder liner portion and the cylinder block body facing the bottom surface. Is the gist.

  According to the configuration, the fastening member for the bolt acting on the upper surface of the cylinder liner portion via the gasket is arranged on the extension line in the acting direction, so the cylinder liner portion caused by the fastening force is arranged. It becomes possible to appropriately suppress the deformation toward the lower side.

The invention according to claim 3 is the cylinder block according to claim 2, wherein the interposed member is disposed along the entire bottom surface of the cylinder liner portion.
According to this configuration, it is possible to appropriately ensure the support rigidity in the entire circumference of the cylinder liner portion.

  According to a fourth aspect of the present invention, in the cylinder block according to the second aspect, the cylinder is a cylinder of a multi-cylinder internal combustion engine, and the interposed member is disposed between the cylinder bores. .

  As described above, when the support rigidity of the cylinder liner portion is not sufficiently ensured, the surface pressure of the gasket, in particular, the surface pressure between the cylinder bores tends to decrease. In this respect, in the same configuration, since the interposition member is disposed between such cylinder bores, it is possible to efficiently suppress a reduction in the surface pressure of the gasket.

  Invention of Claim 5 is the cylinder block assembling method of any one of Claims 1-4, Comprising: While preparing the said some interposition member from which thickness differs, the said cylinder block main body The distance from the surface where the interposed member is disposed to the top surface of the cylinder outer wall portion and the distance from the surface where the interposed member is disposed in the cylinder liner portion to the lower surface of the upper deck portion A difference is obtained, at least one of the plurality of interposed members is selected according to the difference, and the selected interposed member is sandwiched between the cylinder liner portion and the cylinder block body. This is the gist.

  According to this method, the distance from the surface on which the interposed member is disposed in the cylinder block body to the top surface of the cylinder outer wall portion (corresponding to the dimension X), and the interposed member is disposed in the cylinder liner portion. Even if there is a variation in the distance from the surface to the lower surface of the upper deck portion (corresponding to the dimension Y), that is, even if there is a variation in the gap in the portion where the intervention member is disposed, The appropriate thickness of the interposed member is selected. Therefore, variation in the compression amount of the interposed member sandwiched between the cylinder liner portion and the cylinder block body can be suppressed, and thus variation in support rigidity of the cylinder liner portion can be further suppressed. . In selecting an intervention member, a single intervention member may be selected in accordance with the difference (gap) between the distances, and a plurality of intervention members may be overlapped to fit the gap.

Hereinafter, an embodiment embodying a cylinder block and an assembling method according to the present invention will be described with reference to FIGS.
FIG. 1 shows a perspective structure of a main body in an in-line four-cylinder engine 1 to which the present invention is applied. The main body of the engine 1 is largely configured to include a cylinder head 2 and a cylinder block 3. The cylinder head 2 and the cylinder block 3 are assembled by bolt fastening via a gasket 4. A head cover is attached above the cylinder head 2, and an oil pan is attached below the cylinder block 3.

  2A shows a perspective structure of the cylinder block 3, and FIG. 2B shows a side structure thereof. As shown in each of these drawings, the cylinder block 3 is formed with four cylinder bores 5 in the upper part thereof, and in the lower part thereof is provided a crankcase part 31, a so-called cylinder block skirt part. The crankcase portion 31 forms a crankcase in which the crankshaft is accommodated together with the oil pan attached below the crankcase portion 31. On the other hand, on the top of the cylinder block 3, a flat upper deck portion 22 is provided on which the cylinder head 2 is placed and comes into contact with the bottom surface.

FIG. 3 shows a cross-sectional structure of the main body portion of the engine 1 along the line AA in FIG. 1, that is, a cross-sectional structure between cylinder bores.
FIG. 4 shows a cross-sectional structure of the main body portion of the engine 1 along the line BB in FIG. 2, that is, a cross-sectional structure along the central axis of the cylinder bore.

  As shown in FIGS. 3 and 4, the cylinder block 3 is divided and formed by an inner peripheral block 20 and a cylinder block body 30. That is, a cylinder block main body 30 having a cylinder liner portion 21 that constitutes a wall surface of the cylinder and a cylinder outer wall portion 32 that constitutes an outer wall surrounding the cylinder liner portion 21, with a water jacket 6 formed around the cylinder as a boundary. It is divided into and. The cylinder liner portion 21 is integrally formed with the upper deck portion 22, and the cylinder outer wall portion 32 is integrally formed with the crankcase portion 31.

  The inner peripheral block 20 constituting the cylinder liner portion 21 and the upper deck portion 22 is made of, for example, an aluminum alloy or a magnesium alloy, and is integrally cast using a die casting method or the like. And the cylinder liner part 21 of the inner peripheral block 20 is formed in the shape which connected continuously the four circular pipes used as the cylinder liner of each cylinder. The inner peripheral surface of each cylindrical body constitutes the peripheral wall of the cylinder bore 5, and the outer peripheral surface 24 constitutes a wall surface on the cylinder side of a water jacket formed around the cylinder. A protective film made of, for example, iron is coated on the inner peripheral surface of the cylinder liner portion 21 that becomes the surface of the cylinder bore 5 by thermal spraying or the like.

  The upper deck portion 22 is formed in a substantially flat plate shape at the upper end portion of the cylinder liner portion 21. The upper deck portion 22 constitutes the top surface portion of the cylinder block 3. The upper surface of the upper deck portion 22 is a mounting surface 26 on which the cylinder head 2 is mounted, and the bottom surface of the cylinder head 2 is brought into contact with the gasket 4 during assembly. The upper deck portion 22 is formed with a plurality of bolt insertion holes 27 through which the head bolts 7 used for fastening the cylinder head 2 and the cylinder block 3 are inserted.

  The cylinder block main body 30 that constitutes the crankcase portion 31 and the cylinder outer wall portion 32 is also made of an aluminum alloy, a magnesium alloy, or the like, like the inner peripheral block 20, and is integrally cast using a die casting method or the like.

  The cylinder outer wall portion 32 is formed on the upper portion of the crankcase portion 31 so as to protrude upward. The cylinder outer wall portion 32 is formed in a substantially annular shape having an inner peripheral surface 35 formed so as to face the outer peripheral surface 24 of the cylinder liner portion 21 of the inner peripheral block 20. The inner peripheral surface 35 of the cylinder outer wall portion 32 constitutes the outer wall of the water jacket 6 formed around the cylinder.

  A flange 36 is formed at the upper end of the cylinder outer wall portion 32 so as to protrude from the outer periphery to the cylinder bore outer periphery. The top surface 32a of the cylinder outer wall portion 32 on which the flange 36 is formed serves as a receiving surface that abuts and supports the upper deck portion 22 of the inner peripheral block 20.

  Inside the cylinder block main body 30, a hole 40 into which the lower end side of the cylinder liner portion 21 is gently inserted is provided. The inner peripheral surface of the hole 40 and the outer peripheral surface 24 of the cylinder liner portion 21 are sealed by a seal member 61. Incidentally, as the seal member 61, a sealant is applied, rubber, a seal gasket, or the like is used. A hole 41a for a connecting rod is provided on the bottom surface 41 of the hole 40.

  On the other hand, the dimension X from the top surface 32a of the cylinder outer wall portion 32 to the bottom surface 41 of the hole 40 is slightly longer than the dimension Y from the bottom surface of the upper deck portion 22 to the bottom surface 28 of the cylinder liner portion 21. A gap is formed between the bottom surface 28 of the portion 21 and the bottom surface 41 of the hole 40. A shim 70 is disposed in the gap.

  The shim 70 is a member for supporting the lower portion of the cylinder liner portion 21 to the cylinder block body 30 and is sandwiched between the cylinder liner portion 21 and the cylinder block body 30. More specifically, it is sandwiched between the bottom surface 28 of the cylinder liner portion 21 and the cylinder block body 30 facing the bottom surface 28, that is, between the bottom surface 41 of the hole 40.

  FIG. 5 shows a plan view of the cylinder block body 30. As shown in FIG. 5, the shim 70 is disposed in the hatched portion C. That is, it is disposed along the bottom surface 41 of the hole 40, in other words, disposed on the bottom surface 28 of the cylinder liner portion 21 along the entire surface thereof.

  In addition, a plurality of shims 70 having different thicknesses are prepared for the shim 70. When the cylinder block 3 is assembled, an appropriate one is selected according to the combination of the cylinder liner portion 21 and the cylinder block body 30. The That is, first, the difference ΔS between the dimension X and the dimension Y is measured, that is, the size of the gap is measured. Then, at least one of the plurality of shims 70 is selected according to the measured difference ΔS. More specifically, a slight compression allowance α is added to the difference ΔS, and a shim 70 having a thickness equivalent to the added dimension is selected. Then, the selected shim 70 is interposed between the bottom surface 28 of the cylinder liner portion 21 and the bottom surface 41 of the hole 40. The interposed shim 70 is held between the bottom surface 28 and the bottom surface 41 in a slightly compressed state by fastening the head bolt 7. When the shim 70 is selected, one shim 70 may be selected according to the difference ΔS, or a plurality of shims 70 may be overlapped to match the difference ΔS.

  On the other hand, a gap is formed above the hole 40 between the opposed surfaces of the outer peripheral surface 24 of the cylinder liner portion 21 and the inner peripheral surface 35 of the cylinder outer wall portion 32. A water jacket 6 is defined around the cylinder by the outer peripheral surface 24 of the cylinder liner portion 21, the inner peripheral surface 35 of the cylinder outer wall portion 32, and the lower surface of the upper deck portion 22. Incidentally, the water jacket 6 is communicated with the cooling water passage of the cylinder head 2 through a hole provided in the upper deck portion 22.

As shown in FIG. 3, the cylinder head 2 and the gasket 4 are assembled to the cylinder block 3 through fastening of the head bolt 7.
The head bolt 7 is inserted into a bolt fastening hole 37 provided in the cylinder block main body 30 through a hole provided in the cylinder head 2 and the gasket 4 and a bolt insertion hole 27 formed in the upper deck portion 22. . And since it is provided under the bolt fastening hole 37, it is screwed into the threaded portion 37a.

  In this way, the cylinder head 2, the gasket 4, the upper deck portion 22, and the cylinder outer wall portion 32 are fastened and fixed by the head bolt 7, so that the upper portion of the cylinder liner portion 21 is fixed to the cylinder block body 30. Further, the lower side (bottom surface 28) of the cylinder liner portion 21 is also supported by the cylinder block body 30 (bottom surface 41) via the shim 70.

  In the cylinder block of the present embodiment configured as described above, the inner peripheral wall of the water jacket 6 formed around the cylinder is separated from the inner peripheral block 20 side, and the outer peripheral wall is separated from the cylinder block body 30 side. It is molded into the body. Therefore, the shape of the mold part relating to the formation of the water jacket 6 can be simplified. Since the mold shape is simplified, it is possible to greatly reduce casting defects such as a casting cavity and to extend the life of the mold, so that it is easy to form the water jacket 6 around the cylinder.

  On the other hand, in the cylinder block 3 having the divided configuration, when the head bolt 7 is tightened at the time of assembly, the fastening force acts on the upper surface of the cylinder liner portion 21 via the gasket 4, and the cylinder liner portion 21 is It is pressed downward.

  Here, the cylinder liner portion 21 is in a so-called cantilever state only by a fixing mode in which the upper deck portion 22 is supported by the top surface 32a of the cylinder outer wall portion 32 and thereby the cylinder liner portion 21 is fixed to the cylinder block body 30. Therefore, it becomes difficult to ensure sufficient support rigidity of the cylinder liner portion 21. Therefore, the cylinder liner portion 21 is easily deformed downward by the fastening force of the head bolt 7. When the cylinder liner portion 21 is deformed downward as described above, a reduction in the surface pressure of the gasket 4 (particularly a reduction in the surface pressure between the cylinder bores) is likely to occur. Further, the cylinder bore 5 is likely to be deformed due to the downward deformation of the cylinder liner portion 21.

  In this respect, in the cylinder block 3 in the present embodiment, the cylinder block body 30 also supports the bottom surface 28 of the cylinder liner portion 21 in order to suppress such deformation of the cylinder liner portion 21. Therefore, the downward deformation of the cylinder liner portion 21 can be suppressed, and the support rigidity of the cylinder liner portion 21 can be ensured. And the fall of the surface pressure of the gasket 4 can be suppressed by ensuring the support rigidity of the cylinder liner part 21 in this way. Furthermore, since the reduction of the surface pressure of the gasket 4 can be suppressed in such a manner, it is not necessary to excessively increase the fastening force of the head bolt 7, and thus each part (cylinder outer wall portion 32, upper deck portion 21 resulting from the fastening force) is eliminated. Alternatively, deformation of the cylinder head 2 or the like can be suppressed. Further, since the support rigidity of the cylinder liner portion 21 is ensured, deformation of the cylinder bore 5 can be suppressed. Therefore, the roundness of the cylinder bore 5 is improved, and piston friction and the like can be reduced. In addition, since the support rigidity of the cylinder liner portion 21 is ensured, vibration of the cylinder liner portion 21 and vibration noise thereof can be reduced.

  Further, when the lower portion of the cylinder liner portion 21 is supported by the cylinder block body 30 as described above, the shim 70 is sandwiched between the lower portion of the cylinder liner portion 21 and the cylinder block body 30. Therefore, even if the difference ΔS between the dimension X and the dimension Y as described above varies, the variation is absorbed by the deformation (compression deformation) of the shim 70. Therefore, even if the tolerances of the dimensions X and Y are not reduced so much, the degree of pinching of the cylinder liner portion 21 can be stabilized, and variations in the support rigidity of the cylinder liner portion 21 can be suppressed. As described above, in the cylinder block 3 according to the present embodiment, it is possible to secure the support rigidity and suppress variations in the support rigidity without requiring so high accuracy when processing the cylinder liner portion 21 and the cylinder block body 30. it can. That is, the support rigidity of the cylinder liner portion 21 can be more easily ensured as compared to the case where the lower portion of the cylinder liner portion 21 is directly brought into contact with the cylinder block body 30 to ensure the support rigidity of the cylinder liner portion 21. Will be able to.

  Further, the shim 70 is sandwiched between the bottom surface 28 of the cylinder liner portion 21 and the cylinder block body 30 (the bottom surface 41 of the hole 40) facing the bottom surface 28. That is, since the shim 70 is arranged on the extension line of the acting direction (arrow F shown in FIG. 4) of the fastening force of the head bolt 7 acting on the upper surface of the cylinder liner portion 21 via the gasket 4, The downward deformation of the cylinder liner portion 21 due to the fastening force can be appropriately suppressed.

  Further, as shown in FIG. 5, the shim 70 is arranged along the bottom surface 41 of the hole 40 formed in the cylinder block body 30. In other words, the shim 70 is disposed along the entire bottom surface 28 of the cylinder liner portion 21. Therefore, it is possible to appropriately ensure the support rigidity in the entire circumference of the cylinder liner portion 21.

  The shim 70 disposed in the cylinder block 3 is selected in the manner described above. That is, a plurality of shims 70 having different thicknesses are prepared in advance. Further, the distance (corresponding to the dimension X) from the surface (the bottom surface 41 of the hole 40) where the shim 70 is disposed in the cylinder block body 30 to the top surface 32a of the cylinder outer wall portion 32, and the shim 70 in the cylinder liner portion 21. The difference ΔS between the distance (corresponding to the above dimension Y) from the surface (bottom surface 28) on which is disposed to the lower surface of the upper deck portion 22 is obtained. A shim 70 corresponding to the difference ΔS is selected from a plurality of shims, and the selected shim 70 is sandwiched between the cylinder liner portion 21 and the cylinder block body 30. Therefore, even if there is a variation in the difference between the dimension X and the dimension Y, that is, there is a variation in the gap in the portion where the shim 70 is disposed, the shim 70 having an appropriate thickness according to the gap. Can be selected. Therefore, the variation in the compression amount of the shim 70 held between the cylinder liner portion 21 and the cylinder block body 30 can be suppressed, and thus the variation in the support rigidity of the cylinder liner portion 21 can be further suppressed. become.

As described above, according to the cylinder block of the present embodiment, the following effects can be obtained.
(1) The cylinder block 3 is divided into a cylinder liner portion 21 constituting the cylinder wall surface and a cylinder block main body 30 having a cylinder outer wall portion 32 constituting an outer wall surrounding the cylinder liner portion 21. The upper deck portion 22 provided on the top portion of the liner portion 21 is supported by the top surface 32 a of the cylinder outer wall portion 32. Further, a member for supporting the lower side of the cylinder liner portion 21 to the cylinder block main body 30 and a shim 70 sandwiched between the cylinder liner portion 21 and the cylinder block main body 30 is provided. .

  Accordingly, the upper portion of the cylinder liner portion 21 is fixed to the top surface 32 a of the cylinder outer wall portion 32 via the upper deck portion 22, that is, the cylinder block main body 30, and the lower portion thereof is also supported by the cylinder block main body 30 by the shim 70. Therefore, the support rigidity of the cylinder liner portion 21 can be ensured with certainty, and the reduction of the surface pressure of the gasket 4 and the deformation of the cylinder bore 5 can be suitably suppressed.

  Here, in this embodiment, when the lower portion of the cylinder liner portion 21 is supported by the cylinder block main body 30, the shim 70 is sandwiched between the lower portion of the cylinder liner portion 21 and the cylinder block main body 30. Therefore, it is possible to secure the support rigidity of the cylinder liner portion 21 and suppress variations in the support rigidity without requiring so high accuracy when processing the cylinder liner portion 21 and the cylinder block body 30. That is, the support rigidity of the cylinder liner portion 21 can be more easily ensured compared to the case where the lower portion of the cylinder liner portion 21 is directly brought into contact with the cylinder block body 30 to ensure the support rigidity. .

  (2) The shim 70 is sandwiched between the bottom surface 28 of the cylinder liner portion 21 and the cylinder block body 30 facing the bottom surface 28. Therefore, the downward deformation of the cylinder liner portion 21 due to the fastening force of the head bolt 7 can be appropriately suppressed.

  (3) The shim 70 is disposed along the entire bottom surface 28 of the cylinder liner portion 21. For this reason, it is possible to appropriately secure the support rigidity in the entire circumference of the cylinder liner portion 21.

  (4) A plurality of shims 70 having different thicknesses are prepared, the distance from the surface (bottom surface 41) on which the shim 70 is disposed in the cylinder block body 30 to the top surface 32a of the cylinder outer wall portion 32, and the cylinder liner portion 21, the difference ΔS between the distance from the surface (bottom surface 28) where the shim 70 is disposed to the lower surface of the upper deck portion 22 is obtained. Then, at least one of the plurality of shims 70 is selected according to the difference ΔS, and the selected shim 70 is sandwiched between the cylinder liner portion 21 and the cylinder block body 30. Therefore, the variation in the support rigidity of the cylinder liner portion 21 can be further suppressed.

In addition, the said embodiment can also be changed and implemented as follows.
Although the shim 70 is disposed along the entire bottom surface 28 of the cylinder liner portion 21, the shim 70 may be disposed on a part of the bottom surface 28.

  For example, as described above, when the support rigidity of the cylinder liner portion 21 is not sufficiently ensured, the surface pressure of the gasket 4, particularly, the surface pressure between the cylinder bores tends to decrease. Therefore, as indicated by the hatched portion D in FIG. 6, the shim 70 ′ may be disposed only between the bottom surfaces 41 of the adjacent holes 40, that is, the shim 70 ′ may be disposed only between the cylinder bores. In this case, a reduction in the surface pressure of the gasket 4 between the cylinder bores can be efficiently suppressed.

  In order to support the lower side of the cylinder liner portion 21 with the cylinder block body 30, the shim 70 is held between the bottom surface 28 of the cylinder liner portion 21 and the cylinder block body 30 facing the bottom surface 28. However, the position of the shim 70 is not limited to such a position, and the shim 70 is disposed so that the cylinder liner portion 21 is supported by the cylinder block body 30 even at a position below the upper deck portion 22. What is necessary is just to set an installation position. Even in this case, it is possible to suitably ensure the support rigidity of the cylinder liner portion 21 from the upper deck portion 22 to the portion where the shim 70 is sandwiched.

  For example, as shown in FIG. 7, a stepped portion 24′a is provided on the outer peripheral surface 24 ′ of the cylinder liner portion 21 ′, and a space between the bottom surface 24′b of the stepped portion 24′a and the bottom surface 41 ′ of the hole 40 is provided. The shim 70 'may be held between the two.

  -Although the inner peripheral block 20 and the cylinder block main body 30 were made of aluminum alloy or magnesium alloy, those materials may be arbitrarily changed, for example, one or both of them is made of cast iron. For example, if the mechanical strength of the entire cylinder block 3 is secured to some extent on the cylinder block body 30 side, the inner peripheral block 20 should be made of a material that is relatively difficult to secure, such as ceramics or sintered alloy. Is also possible. Further, for the cylinder block body 30 that is not directly exposed to the combustion gas in the cylinder, use of a material having a relatively low heat resistance such as a resin material may be considered.

-Although the inner peripheral block 20 and the cylinder block main body 30 were shape | molded with the die-casting manufacturing method, those manufacturing methods are not restricted to this, You may change arbitrarily.
Although the surface of the cylinder bore 5 is coated with a protective film made of iron or the like by spraying, such processing may not be performed. For example, if a separately manufactured cylinder liner is mounted on the inner peripheral surface of the cylinder liner portion 21 or the inner peripheral block 20 is formed of a material having sufficient wear resistance such as cast iron, the mother The material may be used as the surface of the cylinder bore 5 as it is.

  The cylinder liner portion 21 and the upper deck portion 22 are separate members, and the present invention is the same even when the cylinder liner portion 21 and the upper deck portion 22 are integrated with each other by being appropriately fixed. Can be applied to.

  Although the crankcase body 31 and the cylinder outer wall portion 32 are integrally formed to form the cylinder block main body 30, the crankcase portion 31 and the cylinder outer wall portion 32 may be formed separately. . In that case, the cylinder block 3 has a divided structure by three molded bodies of the inner peripheral block 20, the cylinder outer wall portion 32, and the crankcase portion 31. Employing such a structure is advantageous when the crankcase portion 31 and the cylinder outer wall portion 32 are integrally formed and the shape becomes complicated and the forming becomes difficult.

  In the above embodiment and its modifications, the case where the present invention is applied to the cylinder block of an in-line four-cylinder engine has been described. However, the present invention is not limited to this, and the present invention is similarly applied to a cylinder block constituting an arbitrary type of engine. Can be applied.

The perspective view in the main-body part of an engine about one Embodiment which actualized the cylinder block concerning this invention. (A) is a perspective structure figure of the cylinder block of the embodiment. (B) is the side structure diagram. Sectional drawing along the AA line of FIG. Sectional drawing along the BB line of FIG. The top view of a cylinder block main body. The top view of the cylinder block main body in the modification of the embodiment. Sectional drawing of the cylinder block in the modification of the embodiment. Sectional drawing of the conventional cylinder block.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Cylinder head, 3 ... Cylinder block, 4 ... Gasket, 5 ... Cylinder bore, 6 ... Water jacket, 7 ... Head bolt, 20 ... Inner peripheral block, 21 ... Cylinder liner part, 22 ... Upper deck part, 24 ... outer peripheral surface (of cylinder liner part), 26 ... mounting surface, 27 ... bolt insertion hole, 28 ... bottom face of (cylinder liner part), 30 ... cylinder block body, 31 ... crank case part, 32 ... cylinder outer wall part, 32a ... Top surface (of the cylinder outer wall), 35 ... Inner circumferential surface, (of the cylinder outer wall), 36 ... Flange, 37 ... Bolt fastening hole, 37a ... Screw part, 40 ... Hole, 41 ... Bottom of (hole 40) , 41a ... holes (in the bottom surface 41), 61 ... sealing members, 70 ... shims (intervening members), 21 '... cylinder liner portions, 24' ... outer peripheral surfaces (in cylinder liner portions), 24 a ... step part, 24'b ... bottom face, 41 '... bottom face (70) ... shim (intermediate member), 104 ... gasket, 120 ... cylinder head, 121 ... cylinder liner part, 122 ... upper deck part , 128 ... (bottom of the cylinder liner), 130 ... cylinder block body, 132 ... cylinder outer wall, 132a ... (top surface of the cylinder outer wall), 140 ... hole, 141 ... support part, 141a ... (of support part) Upper surface, 170 ... head bolt.

Claims (5)

The cylinder liner portion that constitutes the cylinder wall surface and the cylinder block body that has the cylinder outer wall portion that constitutes the outer wall surrounding the cylinder liner portion are divided into a substantially flat plate shape provided on the top of the cylinder liner portion. In the cylinder block in which the upper deck part is supported on the top surface of the cylinder outer wall part,
A cylinder block that is a member for supporting a lower portion of the cylinder liner portion to the cylinder block body, and is interposed between the cylinder liner portion and the cylinder block body. . The cylinder block according to claim 1, wherein the interposed member is sandwiched between a bottom surface of the cylinder liner portion and the cylinder block body facing the bottom surface. The cylinder block according to claim 2, wherein the intervention member is disposed along the entire bottom surface of the cylinder liner portion. The cylinder block according to claim 2, wherein the cylinder is a cylinder of a multi-cylinder internal combustion engine, and the interposed member is disposed between cylinder bores. A method for assembling a cylinder block according to any one of claims 1 to 4,
A plurality of the interposed members having different thicknesses are prepared, and the distance from the surface on which the interposed member is disposed in the cylinder block body to the top surface of the cylinder outer wall portion, and the intermediate member in the cylinder liner portion. A difference from the distance from the surface on which the mounting member is disposed to the lower surface of the upper deck portion is obtained, and at least one of the plurality of intervention members is selected according to the difference, and the selected intervention A cylinder block assembling method, wherein a mounting member is sandwiched between the cylinder liner portion and the cylinder block body.

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